Abstract 6-Substituted 1-[(5R, 8S, 10R)-8-ergolinyl]-3, 3-diethylureas II-VII were prepared from hydrazides of (5R, 8S, 10R)-6-alkyl-8-ergolinecarboxylic acids (VIIIa, VIIIb) via the corresponding azides IXa and IXb and isocyanates Xa and Xb, and/or from 1-[(5R, 8S, 10R)- 6-methyl-8-ergolinyl]-3, 3-diethylurea (I) via XI and XII. Two of the by-products arising in the latter route have been identified (XIII, XIV). Some of the ureas prepared, especially II and ...